diff --git a/src/browser/renderer/dom/DomRenderer.ts b/src/browser/renderer/dom/DomRenderer.ts
index 08a54528..da4740ee 100644
--- a/src/browser/renderer/dom/DomRenderer.ts
+++ b/src/browser/renderer/dom/DomRenderer.ts
@@ -27,9 +27,9 @@ let nextTerminalId = 1;
 // font metrics calc settings
 const enum FontMetrics {
   START = 32,         // start codepoint
-  MAX = 1424,         // only calc up to this codepoint
+  MAX = 256,          // only calc up to this codepoint (256 means only Basic Latin + Latin-1 Supplement)
   BATCH_SIZE = 30,    // amount of codepoints to calc in a single batch (sync & blocking)
-  THRESHOLD = 0.005   // relative deviation from cell width
+  THRESHOLD = 0.005   // allowed relative deviation from cell width
 }
 
 /**
@@ -122,8 +122,8 @@ export class DomRenderer extends Disposable implements IRenderer {
     container.style.fontSize = `${this._optionsService.rawOptions.fontSize}px`;
 
     const cellWidth = this.dimensions.css.cell.width;
-    const lower = cellWidth * (1 - FontMetrics.THRESHOLD);
-    const upper = cellWidth * (1 + FontMetrics.THRESHOLD);
+    const lower = 10 * cellWidth * (1 - FontMetrics.THRESHOLD);
+    const upper = 10 * cellWidth * (1 + FontMetrics.THRESHOLD);
     const end = Math.min(this._metricsPos + FontMetrics.BATCH_SIZE, FontMetrics.MAX);
 
     for (let i = this._metricsPos; i < end; ++i) {
@@ -136,7 +136,7 @@ export class DomRenderer extends Disposable implements IRenderer {
 
     const collection = container.children;
     for (let i = 0; i < collection.length; ++i) {
-      const width = collection[i].getBoundingClientRect().width / 10;
+      const width = collection[i].getBoundingClientRect().width;
       this._fontMetrics[i + this._metricsPos] = +(width < lower || width > upper);
     }
     container.remove();
diff --git a/src/browser/renderer/dom/DomRendererRowFactory.ts b/src/browser/renderer/dom/DomRendererRowFactory.ts
index 4bb974a2..0993212d 100644
--- a/src/browser/renderer/dom/DomRendererRowFactory.ts
+++ b/src/browser/renderer/dom/DomRendererRowFactory.ts
@@ -122,6 +122,7 @@ export class DomRendererRowFactory {
       const isNull = cc === NULL_CELL_CODE && width === NULL_CELL_WIDTH;
       const isCombined = cell.isCombined();
       const isLinkHover = isHover && x >= linkState[1] && x <= linkState[2];
+      const isBoldOrItalic = cell.isBold() && cell.isItalic();
 
       if (!charElement) {
         charElement = this._document.createElement('span');
@@ -378,7 +379,12 @@ export class DomRendererRowFactory {
 
 
       // account first char for later merge if it meets the start conditions
-      if ((isNull || (width === 1 && !isCombined && cc < 1424 && !metrics[cc])) && !isInSelection && !isCursorCell) {
+      if (
+        (isNull || (width === 1 && !isCombined && cc < 1424 && !metrics[cc]))
+        && !isBoldOrItalic
+        && !isInSelection
+        && !isCursorCell
+      ) {
         cellAmount++;
       } else {
         // every non-mergeable char gets directly written to its own span